1. Field of the Invention
The present invention relates to an obstacle detection apparatus, method, and medium. More particularly, to an obstacle detection apparatus, method and medium which can detect the state of an obstacle according to a signal generated when the obstacle detection apparatus collides with the obstacle and a change in the posture of the obstacle detection apparatus caused due to the collision with the obstacle.
2. Description of the Related Art
Various types of robots such as robots capable of doing various household chores for users while autonomously moving around in homes have been developed. It is very important for such robots to determine their locations. Thus, a variety of methods have been suggested to enable robots to precisely determine their locations.
Cleaning robots suck up dirt and dust while traveling in a region. It is important for cleaning robots to determine not only their locations but also the locations and shapes of obstacles. In other words, cleaning robots control their suction force or traveling path by determining the locations and shapes of obstacles.
Conventionally, an optical triangulation method has been widely used to determine the location and shape of an obstacle. According to the optical triangulation method, the location and shape of an obstacle can be determined by emitting light with the aid of a light emitter and detecting the amount of light reflected from the obstacle with the aid of a light receptor. The optical triangulation method is based on the fact that the angle of reflection varies according to the distance to an obstacle and a variation in the angle of reflection reduces the amount of light incident on a light receptor or varies a focal point.
The optical triangulation method is robust against noise, and can detect various shapes of obstacles in different locations according to the arrangement of a light receptor and a light emitter.
However, the optical triangulation method may provide distorted measurement results according to the efficiency of reflection on the surface of an obstacle, and is only a one-point measurement method. For example, when the surface of an obstacle is like the surface of a mirror so that the obstacle scatters light only weakly, when the surface of the obstacle is rugged so that the obstacle scatters light irregularly, or when the obstacle is formed of a material that absorbs light and thus does not reflect light, measurement results obtained using the optical triangulation method may be erroneous.
Therefore, it is necessary to develop methods to determine the location and shape of an obstacle regardless of the texture of the surface of the obstacle.